Diaphragm fob phonoobaphs and taiiking-machines



F. VAN V. MORSE. DIAPHRAGM FOR PHONOGRAPHS AND TALKING MACHINES.

APPLlCATlON FILED 3.15.1915.

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Patented Aug. 8, 1916.

attowau FRANK VAN TLECK MORSE, OF MINNEAPOLIS,

MINNESOTA.

DIAPHRAGM; FOB PHONOGRAPHS AND TALKING-MACHINES.

To all whom it may concern:

Be it known that I, FRANK V. V. Monsn, a citizen of the United States, resid ng at Minneapolis, in the county of Hennepin and 5 State of M1nnesota, have invented certam new and useful Improvements Diaphragms for Phonographs and Talking-Machines; and Ldo declare the following to be a full clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates generically to phonographic recorders or reproducers but more particularly to diaphragms used 1n connection therewith..

Oneobject of my invention is to provide a diaphragm that will respond with perfect clearness to the most delicate vibration umspective of atmospheric changes and will accurately record and reproduce both the high and low tones and the included range with equal efiect.

Another and further object of my invention resides in providing a diaphragm that will eliminate almost completely discordant and scratchy sounds now present in phonophic reproductions.

Another and still further object of this in- 8 yention is to provide a diaphragm so mount- I ed as to greatly augment the amplitude of its vibration.

Another and still further' object of my invention is to greatly reduce the cost of diaphragm manufacture.

With these and other objects in view my invention consists of certain novel details of construction, combination and arrangement of parts to be more particularly hereinafter 40 set forth and claimed.

In the accompanying drawings in which corresponding parts are indicated by similar reference numerals; Figure 1 is a front ele- V 'vation partly in section of my improved re-- producer, certain elements being broken away to illustrate the manner of "mounting one of the planes; Fig. 2 is a transverse vertical' section taken on the line 22 of Fig. 1;

- Fig. 3is a vertical section taken on the line 33 of Fig. 2; Fig. 4 is a perspective view of the three elements comprising the diaphragm, said elements being illustrated in separated position.

Specification of Letters Patent.

Patented Aug. 8, 1916.

Application filed February 15, 1915. S erial'No. 8,246.

duction because the annular diaphragms em ployed are more flexible at their central portion than near their periphery and consequently fail to bow uniformly under a given impulse. In other words, nodal points are produced in the length of the diaphragm. Various efforts have been made by constructing diaphragms of several plies of the same or different material or in forming the diaphragm with a graduated thickness from its peripheral to its central portion, the object being to increase the amplitude of vibration of the diaphragm by-strengthening the latter and causing the same to bow uniformly from its medial line, which would thus not only increase the quality of the tone but would also overcome the scratchy-noise produced by the needle in passing over the record.

I have discovered that if two triangular planes of mica of unequal thickness are arranged in coincident relation on opposite sides of an annular celluloid disk which is 'mounted at its periphery in the diaphragm holder and said triangular;- planes of mica secured at their vertices to the diaphragm holder and the three elements united at their central portion to a stylus or reproducing rod that the tones produced by the reproducerwill be much clearer and sweeter than those obtained by reprodueers using the ordinary one ply mica diaphragm and that moreover there will be absolutely no scratchy noises accompanying the reproduction. Thls improved reproduction is caused by the fact the three points at which themica planes are secured to the di'aphragm holder are the nodal points of the diaphragm so that the latter is strengthened at the nodal points as well as at its central portion byreason of the celluloid disk interposed between the mica planes and consequently one impulse given to the reproducing arm orfstylus will l held in place.

cause my improved diaphragm to move bodily or uniformly from its medial line; and further that the amplitude of vibration of the diaphragm will be increased by having the mica planes of unequal thicknesses.

Referring more particularly to the accompanying drawings my invention in its pres ent embodiment consists of an annular diaphragm holder 1, having the flange 2 projecting from one of the peripheral edges thereof. Upon the frame 1 is mounted a bracket 3 which supports a socket 4 adapted to receive a stylus needle 5. Projecting laterally from the central portion of the bracket 3 is an arm 6 secured to which is one end of the stylus or reproducing arm 7, the other end of which is connected to the diaphragm in amanner hereinafter to be stated. A suitable set screw 8 passing through the socket 4 enables the stylus needle 5 to be securely A sounding box 9 is secured by suitable fastening elements on the diaphragm holder 1 as clearly shown in Fig. 2.

As all of the above is Well known to the art, no novelty is claimed in connection with the same it being described simply to enable the application of my invention to be more readily presented.

Coming now to the importantifeature of my invention to wit: the diaphragm, it will t e apparent that the latter consists of the following elements mounted in the, manner hereinafter to be stated: Disposed upon the flange 2 is a rubber gasket 10. Supported upon the gasket 10 at its vertices is a triangular plane of mica 11 and seated upon the mica plane 11 is an annular celluloid disk 12. Resting upon the disk 12 is another mica lane 13 the outlines of which are preferably coincident with the mica planeronthe opposite sides of the celluloid disk 12, said plane 13 being slightly thinner than the plane 11 for a purpose to be described. To support the mica plane 13 in its proper position a rubber gasket 14 is in terposed between the sound Box 9 and the vertices of thexmica plane 13. A fastening element is passed through the central portion of the three planes composing the diaphragm which element is connected to the free end of the reproducing arm 7. A drop of wax about each end of the element passing through the three lanes retains said element in place as will be readily understood without further description.

It is to be noted that the mica planes 11 and 13 are not secured to the celluloid disk 12 except at their vertices and at their centers, and that they are at all times maintained in perfect planes by reason of their not being cemented, as is usually done, They are therefore very sensitive to sound vibra tions and work independently of each other, the thicker plane 11 responding to vibrations which the thinner one 13 would not,

and vice versa. As mica is a material more sensitive to sound vibrations than celluloid, the celluloid disk 12 is placed between the two mica planes 11 and 13 to retard the vibrations of the latter, as will be readily understood without further description.

' From the foregoing construction it will be obvious that owing to the three point connection of the mica planes shown and described as well as the interposed annular disk of celluloid a three ply diaphragm is obtained having such thickness as will enable it to bow uniformly from its medial line under a single impulse given by the stylus arm, thus giving an amplitude for the diaphragm sufiicient to overcome all scratchy and discordant sounds produced by the stylus needl passing over the record and a reproduction free from all defects. Another advantage accruing from my invention is in constructing the same, mica of inferior quality may be employed, whereas the diaphragms now on the market require an exceptional quality of mica. This is an important feature as it greatly reduces the cost of manufacturing diaphragms under consideration.

Although by the foregoing I have set forth certain elements as best adapted to perform the functions allotted to them, nevertheless it is to be understood that various minor changes in form, proportion, etc., may be resorted to within the scope of the appended claims without departing from or sacrificing any of the principles of the invention.

I claim as my invention:

1. A diaphragm for phonographic repr ducers comprising a circular disk of a material sensitive to sound vibrations, and two triangular planes of unequal thicknesses of a material more sensitive to sound vibrations than the material from which said disk is made, said planes being arranged on opposite sides of said disk.

2. A diaphragm for phonographic reproducers comprising a circular disk of a material sensitive to sound vibrations, and two triangular planes-of unequal thicknesses of a material more sensitive to sound vibrations than the material fromwhich said disk is made, said planes working independently on opposite sides of said dis I 3. A diaphragm for phonographlc reproducers comprising a circular disk of a material sensitive to sound vibrations, and two triangular planes of unequal thicknesses of a material more sensitive to sound vibrations than the material from which said disk is made, said planes being arranged on opposite sides of said disk and being secured to the latter only at their vertices and at their cnters, wherebv said planes respond independently to sound vibrations.

4. A diaphragm for phonographlc reproduoers comprising a circular disk of a material sensitive to sound vibrations, and two triangularplanes of unequal thicknesses of l more sensitive to sound vibra- 5 tions than the material from which said disk is made, said planes being arranged in -coi cident relation on opposite sides of said dis and being secured to the latter only at their vertices and at their centers, whereby said planes respond independently to sound 10 vibrations.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesseS- FRANK VAN VLECK MORSE. Witnesses:

J. S. Ammnsou, H. M. Nnwmun. 

